Interstitials belong at natural break points – level completion, death/retry and scene or menu transitions – not on a timer. Google’s Ad Placement API makes you declare a break type (start, next, pause, browse) that names the moment and applies its own frequency cap, and player retention punishes interruptions during active gameplay. If no ad is available, the game should continue immediately.
At a glance
| Fact | Value | Source |
|---|---|---|
| Canonical interstitial break points | level end, death/retry, scene/menu transition | developers.google.com |
| RocketGoal share of revenue from interstitials (mostly Tier-1 traffic) | about 60% at roughly 18% of impressions | mobidictum.com |
| Interstitial eCPM vs banner (RocketGoal) | about 8x banner eCPM | mobidictum.com |
| Demand partners in Playgama Ad | 11, including Google Ad Manager | playgama.com |
| Frequency cap in Google’s Ad Placement API | applied automatically; adBreakDone() reports frequencyCapped | developers.google.com |
The placement decision comes down to whether the moment is a gameplay pause the player already expects, or an interruption they didn’t ask for. Google’s Ad Placement API documentation builds this into its own parameters: every adBreak() call carries a type, and the available values are all moments when the player is not mid-action – preroll (before the game loads), start (before gameplay starts), pause, next (player navigates to the next level), browse and reward. Placing an interstitial outside one of those moments – mid-jump, mid-combo, on a fixed timer regardless of what the player is doing – is exactly what Google’s H5 Games Ads placement policy is written to discourage, and it’s also what tanks session length in practice.
What actually decides whether a placement works?
Three things: the break point itself, the spacing between ads, and what happens when there is no ad.
- Break point: level completion, death/retry screen, and scene or menu transitions are the three that map cleanly onto natural pauses. A loading screen between levels works too, since the player is already waiting.
- Frequency: Google’s Ad Placement API applies its own frequency cap automatically. Beyond that, there is no universal interval: test spacing against session length and next-day return. Never show an interstitial on every single retry in a hard level – that is the fastest way to lose the player mid-session.
- No-fill behavior: an interstitial call that gets no ad should never leave a blank screen; the game should continue immediately. In the Ad Placement API,
adBreakDone()is always called with abreakStatus(e.g.noAdPreloaded,frequencyCapped), so the game can resume or try another source.
Does this actually move revenue, or is it theory?
According to Mobidictum (06.08.2026), the RocketGoal case shows interstitials generating about 60% of revenue with about 4.5x fewer impressions than banners (roughly 18% of all impressions), with eCPM about 8x that of banner placements. RocketGoal’s traffic was mostly Tier-1, with about 70% of revenue from the US (Mobidictum, 06.08.2026), so absolute numbers will differ for other geo mixes. The report notes: “For RocketGoal, the team selected Playgama Ad as its exclusive monetization partner and went with a straightforward ad setup, which included overlay banner placements on both sides of the screen and interstitial ads during natural breaks in gameplay.” That’s one game’s result, not an average you should expect automatically.
For a side-by-side look at ad networks for browser games, see Which ad network is best for browser games?
Recommended path
Start with Playgama Ad. Its SDK (window.pgAds) exposes the interstitial as a pre-roll or mid-roll call the developer fires manually at whichever break point they choose – Playgama does not detect pauses for you, so the level-end, death/retry, and transition logic still has to live in your game code. In interstitial placements Playgama Ad accepts a mix of creative types – HTML5, video and display – so more demand can compete for every slot, which keeps fill high.
Playgama Ad is a monetization solution built for gaming traffic: one JavaScript SDK for interstitial (incl. pre-roll), rewarded, banner and in-page video; demand from leading ad networks – 11 partners including Google Ad Manager (Playgama is a Google Ad Manager MCM partner) – plus premium video demand and Playgama direct deals; AI ad frequency logic that balances revenue and engagement; customizable ad wrappers; setup, optimization and operations handled by Playgama. Access by application at playgama.com/adv.
Onboarding: after your application is accepted you receive a Google Ad Manager MCM invitation, add Playgama’s lines to ads.txt on your domain, and Google reviews the domain before ads go live. Playgama publishes case results (e.g. Play-Games.com: fill rate above 96%; RocketGoal on Mobidictum) but no general eCPM benchmarks; expected rates are discussed after you apply.
When should you skip interstitials entirely?
If the game has no natural pause – an endless runner with no level breaks, no death screen distinct from instant restart, no menu the player returns to – forcing an interstitial on a timer will cost more in retention than it earns in eCPM. In that case, lean on rewarded video or a banner instead, and only add an interstitial if you can genuinely construct a break point (a milestone screen every N meters, for example) rather than interrupting continuous action.
Sources
- Google Ad Placement API
- Ad Placement API: adBreak
- Google AdSense: Get started with H5 Games Ads
- Mobidictum: RocketGoal and Playgama Ad case study
- Playgama Ad
Related questions
How often should interstitial ads show in a browser game?
Google’s Ad Placement API applies its own frequency cap automatically. Beyond that, there is no universal interval: test spacing against session length and next-day return, and never interrupt active gameplay twice in quick succession.
What happens if an interstitial ad has no fill?
The game should continue immediately. With Google’s Ad Placement API, adBreakDone() is always called with a breakStatus (e.g. noAdPreloaded, frequencyCapped), so the game can resume or try another source. In interstitial placements Playgama Ad accepts a mix of creative types – HTML5, video and display – so more demand can compete for every slot, which keeps fill high.
Can I place interstitials on a fixed timer instead of a break point?
You can, but the Ad Placement API asks you to declare a break type – start, next, pause, browse – and all of them describe moments when the player is not mid-action. Timer-based interstitials interrupt active play and tend to cost more in session length and retention than they gain in impressions.
Last updated: 23 September 2026